The present invention generally relates to a method and composition for use in repairing a pipeline, such as a sewer pipe, by installing a liner inside of the pipeline. More specifically, the invention involves the formation of a reinforced lining sleeve, the method of wetting out the fibers in the reinforcing sleeve and the installation of that lining sleeve on inside walls of the pipeline.
There are numerous pipeline conduits that run underground including water lines, sewer pipes, storm water drains, and the like. Over time such pipelines generally deteriorate due to ordinary aging, corrosive action of the fluids being transported in the line, exposure to unusual environmental conditions or for other reasons. As a result, these pipelines often must be repaired to fix holes, cracks and other defects that occur in the line. Despite the cause of the damage, it is important that such a damaged pipeline be mended in order to prevent fluid leakage problems. In some instances the problem may be the result of infiltration, where foreign matter leaks through the cracks and into the material being carried in the pipeline conduit. For example, rust, asbestos, and other substances may flow from the surrounding underground environment into the pipeline and contaminate drinking water. In other instances the problem is exfiltration, where the fluid that is being carried along the pipeline conduit flows outwardly through the cracks leading to a loss of water pressure and other problems.
There are various known methods for renovating existing underground pipelines. Many of these methods employ the installation of a lining hose via the use of a calibration hose. For example, U.S. Pat. No. 4,714,095 (Müller) discloses a method of salvaging an underground sewer pipe with a lining hose and a calibration hose. The lining hose includes an inner layer that is treated with a first resin and an outer layer that is not treated with a resin. The lining hose is placed into the pipe conduit. A calibrating hose, having an outer surface thereof coated with a resin, is introduced into the interior of the lining and expanded to bring the first and second resins into contact with one another while expanding the liner against the interior wall of the pipeline to be repaired. The resins then harden so that the lining hose becomes attached to contact surfaces of the pipeline wall and the calibration hose.
Similarly, U.S. Pat. No. 4,770,562 (Müller) discloses another method of salvaging an underground pipe conduit. A lining hose having an inner layer that is saturated with a resin and an outer layer that is perforated to form flow-through openings for the resin of the inner layer is introduced into the pipeline conduit. Then, the lining hose is shaped to conform to the interior surface of the pipeline by introducing an auxiliary hose into the lining hose and injecting fluid into the auxiliary hose. The resins harden to form a lining structure in the pipeline. After the curing step, the auxiliary hose can be kept in the lining hose or removed by ropes or cables.
U.S. Pat. No. 5,653,555 (Catallo) discloses a method of lining a pipe conduit using multiple curing resins. A lining hose that is coated with a high-strength resin is first positioned inside of the pipeline to be repaired. A calibration hose carrying a layer of corrosion-resistant resin is then inverted into the lining hose to expand the lining hose into contact with the inside surface of the pipeline. The high-strength and corrosion-resistant resin layers are then cured by the application of a heated fluid to the interior of the calibration hose. The cured lining hose and calibration hose form a rigid self-supporting structure on the interior of the pipeline.
In another Catallo reference, U.S. Pat. No. 5,680,885, a method of rehabilitating a damaged pipe conduit using a lining hose and calibration hose is disclosed. The inner layer of the lining hose is soaked with an excess volume of resin while a calibration hose installed therein contains a resin-absorbent layer. The calibration hose is installed by inverting it using pressurized heated water. After inversion, the resin-absorbent layer of the calibration hose contacts and adheres to the resin coated layer of the lining hose. Upon curing, the calibration hose becomes an integral part of the liner.
Finally, U.S. Pat. No. 5,706,861 (Wood) discloses a method of lining a section of a pipeline by a “cured in place” system using a lining tube and inflatable bladder. The lining tube is impregnated with a curable synthetic resin and is carried into the pipe conduit on an annular inflatable bladder. The bladder is inflated and the lining tube is cured to the pipeline. Then, the bladder is peeled away from the cured lining tube and removed from the pipe conduit by ropes.
Although the above-described conventional methods may be somewhat effective in repairing pipelines, they still suffer from various problems. For example, problems arise concerning the inversion of a felt liner because it is relatively delicate and tends to break or rip during the inversion process. While the use of reinforcement in the liner is desirable, due to the manner in which the liners are handled during installation, typical reinforcement fibers that are not fully wetted out have the tendency to break. Moreover, while carbon fiber is highly desirable as a reinforcing fiber, it is only effective in multiple plies and it is extremely difficult to properly wet out.
In view of the foregoing, there is a need for a pipe liner that effectively incorporates carbon fiber reinforcing. Further, there is a need for a pipe liner composition and method of installing that pipe liner composition that allows the use of multiple layers of carbon fiber reinforcing while ensuring the proper wet out of the carbon fiber prior to installation thereof. Finally, there is a need for a method of installation of a pipe liner that employs carbon fiber reinforcing that facilitates proper wet out of the fibers prior to installation thereby greatly reducing breakage of the fiber reinforcing due to the handling and installation thereof.